Olefinic polymerization process and product



Patented Aug. 22, 1944 UNITED STATES. PATENT OFFICE,

OLEFINIC POLYMERIZATION PROCESS AND raonuo'r William J. Sparks, Elizabeth, and Robert Thomas, Union, N. J., assignors, by mesne assignments, toJasco, Incorporated, a corporation of Louisiana No Drawing. Application August 30, 1941, Serial No. 408,992

22 Claims. (01. goo-79y active with Sulfur.

This invention relates to hydrocarbon polymers; relates particularly to ipterpolymers or polymers of an isoolefin'with a polyolefin; and relates especially to sulfurizable interpolymers of an isoolefin with a monomethyl substituted butadiene.

As shown in our copending application, Serial No. 182,252, it'has been found possible to produce an interpolymer of an isoolefin such as isobutyl- 'ene with a diolefin such as butadiene by a low temperature technique, utilizing an active metal halide, or Friedel-Crafts type, catalyst dissolved in a low freezing solvent. The resulting polymers have molecular weights ranging from 15,000 to 150,000or above, and are reactive with sulfur in a curing reaction by which the elasticity of the polymer is'largely destroyed and replaced by an elastic limit at which the material'has a tensile strength ranging from 2,000 to 5,000 pounds per square inch and an elongation ranging from 300% to 1200%. I

The resulting polymers are high grade materials suitable for replacement of natural rubber for many of its uses. The polymer does not, however, have all of the characteristics of natural rubber, nor all of the characteristics desirable for some particular uses, and, accordingly, means i for modifying the characteristics of the material to adapt it to particular uses areimpor'tant.

The present invention presents a new interpolymer, an interpolymer in which an isoolefin,

- preferably isobutylene, or, alternatively, B-methyl may be used. These two diolefins may be identifled as the C- dienes, or compounds having the formula C5Ha.

These diolefins polymerize readily with the isoolefins, as above outlined, and yield very valuable high molecular weight polymers, which are re ride, bromide or iodide or uranium ortitanium They are solids, have iodine numbers within the range of 1 to 50, and molecular weights within the range of 15,000 to 150,000, or even higher, up to 300,000, and when cured with sulfur yield rubber-like substances which have elastic limits and tensilestrengths at break ranging from. 2,000 to 5,000 pounds per square inch, and elongations at break ranging from 500 to 1200%.

Thus an objector the present invention isto I interpolymerize an isoolefin suchv as isobutylene with a methyl substituted conjugated dioleflns such as isoprene or piperylene, to modify and improve the characteristics of .a low temperature rubbery interpolymen, Other objects and details of the invention will be apparent from the followingdescription. I

In practicing this invention, an olefinic mixture is prepared, consisting of the isoolefin, preferably isobutylene, with the diolefin,which may be either isoprene or piperyline; the isoolefin preferably being present in the ratio of from to 99 parts, with the diolefin in a proportion of 20to 1 part. Thisoleflnic mixture is preferably diluted with a diluent-refrigerant such as liquid ethylene. or liquidethaneor liquid methane or mixtures of these several diluent-refrigerants together with other inert diluents such as liquid propane, liquid butane, liquid ethyl or methyl chlorides and the like, the diluent-refrigerant being present in theproportion of from 2 to 5 or 6 volumes per volume of mixed olefins. Alternatively, an excess of, solid carbon dioxide may be utilized either with or without an auxiliary diluent such as, propane, ethyl or'methyl chloride or similar inert low freezing substances. If desired, external ,coollng may be used, the'r eaction mixture being circulated ,rapidly. past a cooling surface, such as a series of tubes submerged in a convenient refrigerant.

The catalyst preferably consists of a solution of an active metal halide such as aluminum chlochloride dissolved in a low freezing solvent such as/ethyl or methyl chloride or liquid carbon dioxide or similar homologous substance. The catalyst solution is preferably applied in the form of a spray or mist on to the surface-of the rapidly stirred mixture of the olefins and diluent-refrigerant. The reaction proceeds rapidly to produce the desired solid, plastic, elastic polymer.

The preferred diluent-refrigerant is 'liquid' ethylene, but superior interpolymers are produced from some of theabove indicated reactants by the use of lower temperatures-than the -98- C. to 103 C. which is obtainable" by liquid ethylene. For this purpose, liquid methane or mixtures of liquid methane and liquid ethylene are preferably used with temperatures ranging from l10 down to the minlmum'temperamethyl thiuram disulfide).

ture obtainable with liquid methane inthe neighborhood of 161 C. At temperatures below 100 C. care must be used in regard to the catalyst solution, the solution being chilled before use only to a temperature above its melting point before application to the mixed olefins preferably through a spray nozzle.

appropriate fillers, plasticizers and the like, and suitable suliurization aids such as .'I uads" (tetraso compounded, is cured into an elastic, rubber- The polymer, when like substance having an elastic limit, a' high" tensile strength and a high elongation by the application of heat within a temperature range of 135C. to 185 C. for a time interval ranging from 1 5 to .12 0 minutes.

prepared with one part of piperylene and 4 volumes of liquid ethylene were added to the mixed 0., the Tuads added .quickly and the compound removed from the mill.

This prepared compound was then placed in a mold and cured at a temperature of 155 C. for GO-minutes to produce the desired cured rubberlike polymer. This cured compound was found to'have a tensile strength of 3700 pounds per The polymer may be combined with sulfur and i squar in d n ati n of app i at y 1100% at break.

. EXAMPLE 3 An olefinic mixture containing isobutylene in the proportion of 99 parts with the above mentioned isoprene in the proportion of 1 part, was prepared as in Example 1 and polymerized in the presence of liquid,ethylene as a diluent-refrigerant by the application of a similar catalyst, to

olefins. v The mixture was prepared in a reactor of the refrigerant byambient heat. The catalyst was prepared by dissolving commercial anhydrous aluminum chloride in methyl chloride at the boiling point of the methyl chloride to yield a nearly saturated solution containing approximately 6%of'aluminumchioride. This solution was then diluted with an additional amount of methyl chloride to produce a solution containof dissolved commercial aluminum ing 0.5% chloride. This solution was then precooled to a temperature of about ''78 0., and sprayed through a spray nozzle on to the surface of the vigorously stirred mixed olefins. The polymerifeatures are obtained by the use of these Cs conjugated diolefins instead of butadiene.

The C0 conjugated diolefins interpolymerize very readily with the isooleflns, particularlywith isobutylene;

and interpolymerize in nearly the proportions in which they are present in the mixture, in sharp contrast to butadiene, which interpolymerizes with great difliculty and in much lower proportions than the proportion in which itis present zation proceeded rapidly and was approximately 80% complete in about 5 minutes.

. EXAMPLE 2 The interpolymer of isobutylene and piperylene was then compounded according to the following formula:

Interpolymer 100 Zinc oxide 5 Stearic c a Sulfur 3 Tuads 1 In preparing this compound, the interpolymer was worked briefly upon the mill for a time interval of approximately 5 minutes. Then the zinc oxidewasadded and thoroughly incorporated into the polymer by further working on the mill.

Thereafter, the stearic acid and sulfur were simultaneouslyadded, the mill temperature during this portion of theoperation being maintained at approximately 140 C. When these 111 gredients were thoroughly incorporated, the mill was cooled to a temperature of approximately 40 tion.

in the mixture. Also, in the obtaining of a given proportion of interpolymerized diolefln in the polymer molecules, the C5 conjugated dioleflns show a markedly lower poisoning eifect thus making it possible to obtain an interpoiymer of higher molecular weight.

Also, the C5 conjugated dloleflns yield a polymer which when cured is of conspicuously high resistance to ozone and aging in general, in contrast to some of the other diolefins which yield material of lower resistance to'ozone and oxida These characteristics are well shown in the following table:

HTABL'B I Characteristic properties of butyl rubber from various diolefins I Te sil st th Per cent MOI t n e reng Per centelongatlon 010mm weight 555"? BUTADIENE- (CONTROL) ISOPRENE In this table the amount of the several dioleflns added ,i is ixiven; together "with the molecular weight obtainable, the molecule percentage'of I .unsaturation, which .islpractically, equivalent ;.to the number of diolei'inmoiecules'perlqoflmolecules, the tensile 'lstren'gth and. the percent elongation at break of the various cured stocks.

Thus the invention provides a new and useful interpolymer isooleflnwith a CsHs hydrocarbon,

particularly in a methyl substitute buta'diene in which the characteristics oflthereaction-iare While there are above disclosed but a limited number of embodiments of the invention, iitis possible to produce still other embodimentswithout departing from the inventive concept herein' disclosed, and itis, therefore, gdesired thatraonly such limitations be imposed upon the appended claims as are stated therein or; required by the Drior'art. v 1 Y a The invention claimed is:

1. The process oi preparing a solid plastic by: drocarbon interpolynier which is reactive with suli'ur to give an elastic product comprising the steps of reacting together a major proportion .of

an aliphatic isooiefin 'havingtto '1, inclusive, I carbon atoms per molecule, with a minor pro-.

portion of an aliphatic diolei'in'having 5 carbon atoms per molecule, at a temperature between" C. and -160 C; in the presence of apolymerization catalyst comprising a Friedel-Craits' cata-' 'lyst dissolved in a solvent which forms nocomplex with the Friedel Craftsc'atalyst"and'is liquid at the reaction temperature. 1 i

2. The process oir'preparing solid, plasti'cphydrocarbon interpolymer comprising the step of reacting together a low m'olecular weight aliphatic isoolefin having less than 8 carbon atoms per molecule with a 'iow molecular weight'aliphatic dioleiin having carbon atoms per molecule in the presence of aFriedel-Crafts catalyst dissolved in a solvent which forms no complex 65 with theFriedel-Craitscatalyst and is liquidwat the reaction temperature, the reaction being conducted at a temperature below 0 C.

3. The process of preparing solid, plastichydrocarbon inter-polymer .which is reactive with a sulfur to give an elastic product comprisingthe step of reacting together a major proportion'ot isobutylene with a minor proportion-oi a low molecular weight aliphatic conjugated 'dioleiin having 5 carbon atoms per molecule in the presence of a Friedel-Crai'ts catalystdissoivedin aan organic solvent which forms no complextherewith and is liquid at the reaction temperature,

the reaction being conducted at a temperature sulfur to --give anelastic-product comprising the between 0 C. and -160' C.

4. The process of preparing solid, plastic hydrocarbon interpolymers which are reactive with sulfur to yield an elastic product comprising the step 01 reacting together a major proportion of isobutylene with a minor proportion of isoprene "in the presence of a Friedel-Crafts catalyst dissolved inasoivent'w'hioh' forms no complex ithere- 'with and i's liqu'id-at the reaction temperature; the

reaction'kbeing conducted at a temperature :bei s;tween0jicz and metic. *fbf'a'lhemprocess eta-preparing-solid,i'piastic hy- -i-drocarbon interpolymersr'whichiare reactive with sulfur to yieldan elastic product comprising the step of .reacting togetheraaz'v major proportion of ois-isobutylene witheaeminorgproportion of t-pent'a- :diene in I the presence ofr'avFriedel crafts" catalyst.

iidissolvedi inaa: solvent which forms. no a complex therewith and -islliquidrat-ethe -reaction tempera- .1 turef thexreactio *beingconducted at-za tempera- V Q 6. EThejprocess: -'of preparing solid, plastic rhyvdrocarbon linterpolymersrwhichi are' reactive with sulfur to 'yieldaa'n:Pelastic; productcomprising the step of reactingwtog'ether a majorcproportion 01' F isobutylene* witlv-a uhinor,qproportion"of isoprene in the-ypresenee of aluminum; chloride dissolved i @in asolvent wh'ich, iormsv no 2 complex therewith i'andis liquidkat the'rea'ction. temperature;the reactionbeing-conducted":at a temperature between drocarbon interpolymersywhich are" reactivewith sulfur to yieldzan elastictproduct comprisingthe step oi-"reactin together a maior proportion of isobutylene;wtihsaminor-proportion of'pentadiene in'ithepres'enceoi 'aluminum chloride dissolved in a sol jvent -whichiorms no eomplex'therewith and is li'quid at the reaction-temperature, the reactiorrbeingconducted ata 'temperature between ,BJFThe process iof preparing solid; plastic, hy

drocarbon interpolyrners which are reactive with sulfur. to give amelastic product comprisingthe step of reacting: togethera. major proportion of isobutyiene withi-a'minor proportion of a low molecular :weight aliphatic conjugated diole'fin having '5 carbon atoms perjmo'lecule in the presence-of aluminum" chloride .tdissoived in an alkyl halide which 'forms'no complex with the aaluminumlchlorideiandisfliquid at the reaction j temperature, the reaction being conducted at a temperature betweenfOl C. and 160 C.

9. The process of,. preparing' solid, plastic, "hydrocarbon interpolym-ers which are. reactive with sulfur to givean'elasticproduct comprising the step t of: reactingi rtogethervaz' majorg proportion of isobutylene withca minor, proportion of isoprene in the presence of aluminum chloride dissolved in aluminum chloride an'd isniiquid at the reaction temperature,=' the reactionv beinguconducted eat a temperaturebetween -0' lC:-and- C.

1 1 The process of :.preparing solid, plastic, hydrocarbon interpolymers which are reactive with step of reacting? togetherharmajor proportion of isobutylene witm a minor. proportion of isoprene in the presence of aluminum chloride dissolved inmethyl chloride, the reacti'onbeing.v conducted at "-atemperature between -.50 C.and -'160 C.

an alkyl halidewhich 'forms no complex with the I 12. The process of preparing solid, plastic, hydrocarbon interpolymers which are reactive with a sulfur to give an elastic product comprising the step of reacting together a major proportion of isobutylene with a minor proportion of pentadiene in the presence of aluminum chloride dissolved in methyl chloride, the reactionbeing conducted at a temperature between }50 C. and 160 C.

hydrocarbon. interpolymers comprising the step of reacting together a major proportion of isobutylene with a minor proportion of isoprene in the presence of a Friedel-Crafts a catalyst dissolved in an organic solvent which forms nocomplex therewith and is liquid at thereaction temperature, the reaction being conducted at a temperature between 50 C. and l60 C. and thereafter heating the polymer with sulfur and a sulfurization aid.

.15. The process of preparing cured, solid, elastic hydrocarbon interpolymersv comprising the step of reacting together a major proportion of isobutylene with a minor proportion of pentadiene in the presence of a Friedel-Crafts'catalyst dissolved in an organic solvent which forms no complex therewith and is liquid at the reaction temperature, the reaction being conducted at a temperature between 50 Cfand 'l60 C. and thereafter heating the polymer with sulfur and a sulfurization aid.

16. The process of preparingcured, elastic, hy-

drocarbon interpolymers comprising the step of reacting together a major proportion of isobutylene with a minor proportion of a low molecular weight, aliphatic, conjugated diolefin having butylene with a minor proportion of isoprene in the presence of a Friedel-Crafts catalyst dissolved in asolvent'which forms no complex therewith and is liquid at the reaction temperature, the reaction being conducted at a temperature between 50 C. and --160 C., and thereafter heatingthe polymer with sulfur and a sulfurization aid comprising tetramethyl thiuram disulfide.

, 18. The process of preparing cured, elastic, hydrocarbon interpolymerscomprising the step of reacting together a major proportion of isobutylene with a minor proportion'of pentadiene in the presence of a Friedel-Crafts catalyst dissolved in a solvent which forms no complex therewith and is liquid at the reaction temperature, thereaction being conducted at a temperature between 50 C. and -16 0 0., and thereafter heating the polymer with sulfur and a sulfurization aid comprising tetramethyl thiuram' disulficle. t

19. A synthetic, solid, plastic, hydrocarbon interpolymer of a major proportion of an isoolefln having less than 8 carbon atoms per molecule with a minor proportion of diolefin having 5 carbon atoms per molecule, the said polymer being characterized by a low unsaturation below an iodine number of 50, a molecular weight above 15,000 and reactivity with sulfur to yield a product of increased elasticity.

' having 5 carbon atoms per molecule, the polymer being characterized'by a low unsaturation below an iodine number of 50, a molecular weight above 15,000, and reactivity with sulfu'r to yield an elastic product.

21. A synthetic solid, plastic, hydrocarbon interpolymer of a major proportion of isobutylene with a minor proportion of isoprene, the polymer being characterized by a low unsaturation below an iodine number of 50, a molecular weight above 15,000, and reactivity with sulfur to yield an elastic product. 1

22. A synthetic solid, plastic, hydrocarbon interpolymer of a major proportion of isobutylene with a minor proportion of pentadiene, the poly-.

mer being characterized by a low unsaturation below an iodine number of 50, a molecular weight above 15,000, and reactivitywith sulfur to yield an elastic product.

WILLIAM J. SPARKS. ROBERT M. THOMAS. 

